The Murine Hematology/Coagulation Core's primary function is to check for hematological and related metabolic abnormalities in the different mouse strains produced by different Projects. The following tasks will be carried out by this core: 1) Identifying abnormalities in blood cell number and morphology, and abnormalities in hemostasis. Measurements will include: a) Hematological parameters: quantitation of red blood cells, white blood cells (including subsets), and platelets in whole blood. b) Hemostatic parameters: bleeding time, prothrombin time (PT), activated partial thromboplastin time (APTT), and thrombin time. c) Fibrinolytic parameters: dilute whole blood clot lysis time. d) Anticoagulation parameters: protein C, protein S and antithrombin activities. 2) Identifying abnormalities in endothelial cell function with respect to hemostasis. The effect of genetically altered endothelial cell surface glycosaminoglycans (project #5) upon blood coagulation and fibrinolysis will be assessed by use of endothelial cell cultures derived from different tissues of control and transgenic mice. Cell surface related activities of tissue factor/VIIa, antithrombin, TFPI, and plasminogen will be measured. If the endothelium-targeted transgenic mice produced in projects #1 and 4 show evidence of thrombosis, similar studies will be carried out with the corresponding tissue cell cultures. 3) Screening for abnormalities of liver function and other metabolic derangements. A panel of chemistry tests will be established to evaluate the overall function of the liver and the metabolic status of control and transgenic mice. When abnormal test results are found in one of these screening tests, further studies will be performed as needed, in close co- operation with the individual project leaders.